v1 alg image updates

[notkevin888]

Fixes #25 and #26.

• manually swapped copp/cadj and cadj/copp (as well as updating source spreadsheet)
• manually converted descriptions mentioning white/yellow to reference U-color/D-color (as well as updating source spreadsheet)
• changed cubicle_embed.html to use yellow-top white-bottom (instead of vice-versa - other sides don't matter for us)
• switched /learn/cases.html and _layouts/case.html to dynamically fetch images from embed, rather than using incorrect static image

Created #27 to look into faster image load times (particularly for /learn/cases)